Microsoft Visual Basic 2010 Step by Step eBook

Chapter 11 Using Arrays to Manage Numeric and String Data 295

If you want to focus on array operations without displaying the results, place a comment

character (‘) before each line of code that manipulates a text box object to “comment out”

the text box (but not the progress bar) portions of the program. You’ll be amazed at how fast

array operations run when the results do not need to be displayed on the form. (An array of

100,000 elements loads in just a few seconds .)

Chapter 11 Quick Reference

To Do This

Create an array Dimension the array by using the Dim keyword. For example:

Dim Employees(9) As String

Create a public array Dimension the array by using the Public keyword in a module. For example:

Public Employees(9) As String

Create a public array

specifying upper and

lower bounds

Dimension the array as described earlier, but also use the To keyword. For

example:

Public Employees(0 To 9) As String

Note: The lower bound of the array must always be zero (0).

Assign a value to

an array

Specify the array name, the index of the array element, and the value. For

example:

Employees(5) = "Leslie"

Declare an array

and assign values to

it at the same time

Specify the array name, an array type (optional), and the values for the

array enclosed in braces. For example:

Dim Waiters() As String = {"Ben", "Sue", "Lee", "Kim", "Pat"}

Format text strings

with carriage return

and tab characters

Use the vbCrLf and vbTab constants within your program code. (To add

these values to strings, use the concatenation operator (&) .)

Create a dynamic

array

Specify the name and type of the array, but omit the number of elements.

(If the array has multiple dimensions, insert commas but no numbers

between the dimensions .) In your program code, specify the size of the

array by using the ReDim statement. For example:

ReDim Temperatures(10)

Process the elements

in an array

Write a For... Next loop that uses the loop counter variable to address

each element in the array. For example:

Dim i As Short

Dim Total As Single

For i = 0 To UBound(Temperatures)

Total = Total + Temperatures(i)

Next

Redimension an array

while preserving the

data in it

Use the Preserve keyword in your ReDim statement. For example:

ReDim Preserve myCube(25, 25, 50)